Rumbling barrel



M. A. ROLLMAN RUMBLING BARREL Aug. 7, 1934.

Filed June 2, 1931 WWW Patented Aug. 7, 1934 Q UNITED STATES PATENT OFFICE RU BmNGBAimEL Michael A. Bellman, Mount Joy, Pa; Application mm, 1931, Serial No. 541,731 Claims. (01. 220-89, J

"This invention relates to that class of rumbling barrels used for rumbling cast-iron articles. As is well known, slight traces of, the acid used inthe pre-cleaning of the'cas tings remain on the castings when they are dumped into the rumbling barrel and that this acid occasionally generates enough-'gas'to burst the barrel during the rumbling operation. Attempts have been made to avoid this destruction of the barrel '1 by employing relief valves, but these valves have not been successful because of the fact that the water used in the rumbling operation makes a slush which interferes with the proper operation of safety valves. It is the object of my present invention to provide what might be termed broadly a safety valve for permitting the dangerous pressure to relieve itself to thus avoid the ruination of the barrel by the bursting thereof.

In the drawing annexed;

Fig. 1 is a side elevation of an ordinary octagonal rumbling drum or barrel provided with my pressure relieving device which in the present instance is in the form of a cover for the usual filling and emptying opening formed in one of the octagonal walls of the valve.

Fig. 2 is a face view of my cover removed. Fig. 3 is a vertical sectional view taken on the line 33 of Fig. 1, only a portion of the barrel being illustrated.

Fig. 4 is an inside view of the cover. Fig. 5 is a longitudinal sectional view of the cover, and

Fig. 6 is an enlarged sectional view of the pressure relieving plate taken through two of the pressure-relieving grooves formed therein.

Referring to the drawing annexed by reference characters, 10 designates a rumbling barrel of the usual form, having a filling and emptying 0 opening 11 in its wall, this hole extending longitudinally of the barrel. Clamped removably over this hole 11 by means of suitable clamps 12 is a cover consisting of a heavy cast-iron frame 13, which is engaged by the aforesaid clamps 12, and which clamps against the outer face of the barrel a thin steel plate 14, this plate being desirably fastened tothe inner face of the covering 13 by means of screws 15. This steel plate 14 extends over the entire area of the hole 11 and 15 forms virtually a cover therefor. Formed in the inner face of this plate 14 is a series of grooves 16, three being shown in the present instance. These grooves or cuts extend nearly through the plate, the bottom of the cuts stopping just short 1 of the outer face of the plate. Covering and protecting the grooved area of the plate is a grating composed of parallel bars 17- mounted rigidly in transverse bars 18 fastened to the plate 14 by screws 19-, the object of this grating being to prevent the tumbling castings from making direct contact with the inner face of the pressure-relieving plate 14 adjacent'the grooves.

With the cover plate thus constructed, in case any excess of pressure is generated in the barrel during the rumbling operation, the outward pressure against the cover plate 14 will cause a slit or opening to occur at one or more of the grooves 16, as shown at 20, Fig. 6, and thus permit the gases to escape intothe atmosphere. The pressure breaks the metal along the line of the bottom of the groove, the metal being thin enough along this line to permit this to be done under a predetermined pressure. Immediately after the pressure is relieved by the escape of the gases the grooves begin to fill with wet sand 16, as the barrel rotates, until finally (after a few revolutions) the sand entirely seals the slit. Until this resealing is accomplished there is a slight leakage of water but the amount of leakage is negligible. If the pressure again accumulates to a sufficiently high degree the sand seal will be blown out and the pressure again will be relieved and this operation will be repeated until the rumbling operation is completed. I found in practice that it is well, about once a month or so, to hammer back the edges of the slits to a flat position to thus restore the device approximately to its original condition.

In Fig. 7, I show a slight modification. In this modification instead of using a single plate with partly-cut through grooves on the inside of the plate, I build up the plate of two or more independent sections 14 with their adjacent edges closely abutted to form practically a joint that will be under normal conditions water tight so as to prevent leakage. The adjacent edges of this abutted joint are bevelled off at 14 to not only provide a sealing groove on the inner face of the cover plate but also to thin down the abutting edges of the plate at this point to enable said abutting edges to be bulged outwardly by the pressure to thus permit the gas to escape.

It will be understood that the weakened lines and grooves need not be straight; they may be curved or diamond shaped or otherwise shaped without departing from my invention.

I claim:

1. A rumbling barrel having an opening in its Wall, a cover plate for said opening embodying a plate structure of elastic metal secured tightly over the opening and provided with a weakening groove in its inner face, whereby excess pressure in the barrel will cause the plate struc- 5 ture to open along said groove and thus form a gas escape opening and whereby also the groove will form a pocket for resealing the opening through the medium of the wet sand in the barrel. r

2. A rumbling barrel having an opening in its wall, a cover for said opening embodying a plate of elastic metal secured tightly over the opening and provided with a groove in its inner face extending partly through the sheet, whereby excess pressure in the barrel will cause the plate to crack along said groove and thus"f0rm a,

temporary escape opening.

3. A rumbling barrel having an opening in its T wall, a cover for said opening embodying a plate of elastic metal secured tightly over the opening" and provided with a groove in its inner face extending partly through the sheet, whereby excess pressure in the barrel will cause the plate to crack along said groove and thus form a temporary escape opening, a guard being arranged over the inner face of said plate of elastic metal coincident with said groove to 7 said groove and thus form a temporary escape opening, a guard being arranged over the inner face of said plate of elastic metal coincident with said groove to thereby prevent the rumbling castings from striking the plate at or adjacent to the groove, said guard consisting of a plurality of parallel bars fastened to the inner face of said .plate.

5. A rumbling barrel having an opening in its wall, a cover'for'said opening embodying a plate of elastic metal screwed tightly over the opening'and consisting of a plurality of sections having; their edges arranged in'tightly abutting relation, a groove being formed along said abut-- ting edges on the inner face of the plate to .thus weakenthe plate along that line and to form a sealing pocket.

MICHAEL A; ROLLMAN. 

